\(I_D\)  and \(I_R\)  are the original image \(I_s\)  erased by the mask \(M_D\)  and \(M_R\)  respectively. They can inform the HDRNet where to focus and how to inpaint these two regions with partial convolution [1]}. In addition, the modal mask of the right hand \(M_{rv}\)  and the modal mask of the background \(M_{bv}\)  point out where the HDRNet can refer to for de-occlusion and removal respectively.
Formally, \(I_D\) , \(I_R\)  and \(M_{bv}\)  are computed as follows:
\(\begin{aligned}& I_D =I_s \cdot (1-M_{D}), \\& I_R =I_s \cdot (1-M_{R}), \\& M_{bv} =(1-M_{ra})\cdot (1-M_{la}).\end{aligned}\) 
